Manufacturing thermostats



(No Model.)

M. MARTIN.

MANUFACTURING THERMOSTAIS'.

Patented Nov. 3. 1885.

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PATENT MANUFACTURING TH ERMOSTATS.

SPESIEICATION forming part of Letters Patent NO. 329,469, dated November 3, 1885.

Serial No. 157,042. (No model.)

To all whom it may concern:

Be it known that I, MoRRIs IlIARTIN, of Malden, county of Middlesex, State of Massachusetts, have invented an Improvement in Methods of Manufacturing Thermostatic Instruments, of which the following description, in connection with the accompanying drawing, is a specification, like letters on the drawing representing like parts.

My invention relates to a method of manufacturing thermostatic instruments operated by a rise in temperature to produce a signal or otherwise to make known such rise in temperature, the instrument operating by the vaporization of a volatile liquid in a metallic reservoir having a flexible side, which is expanded by the liquid in vaporizing. The reservoir is preferably made oftwo metallic plates or disks, united around their edges by solder, thus forming a chamber to contain the volatileliquid, and itis necessary to provide means for introducing the liquid to the said chamber and subsequently sealing the latter tightly. As the liquid employed usually volatilizes at a very low temperature, it is difficult, if not impossible, to unite the portions of the reservoir by solder after the liquid has been placed between them, owing to the heat required for soldering, and instruments of this kind have been devised in which the reservoir is pro vided with a screw-hole, through which the liquid is inserted,and which is afterward sealed by applying a screw in the said hole. This construction is expensive, and does not always afford an absolutely tight reservoir, as is essential for the proper operation of the instrument.

In order to introduce the volatile liquid into the reservoir in accordance with the present invention, I provide the reservoir with a small hole near one edge, and introduce the liquid by immersing the said reservoir in the liquid and pressing the sides of the reservoir together in order to expel the air, so that when the pressure is relieved the reservoir, by its natural elasticity, will expand and draw in a sufficient portion of the volatile liquid. The res ervoirs thus provided with liquid are then placed in a cool body, preferably cold water or a freezing-mixture, which surrounds them nearly up to the level ofthe hole through which the liquid was introduced, the portion of the reservoir containing the said hole projecting above the cool body. The hole may then be closed by soldering, in the usual manner, the cool body surrounding the main portion of the reservoir preventing the contained liquid from being volatilized by the heat applied to the upper edge of the reservoir for the purpose of soldering.

The drawing shows the reservoirs surround ed by cooling material, to enable the same to be soldered in accordance with this invention.

The reservoirs a. consisting of a flat chamber having flexible sides, are each provided with an opening, b, near its edge, through which the volatile liquid is introduced, after which the said reservoir is placed edgewise in a cool body of freezing-mixture, c, surrounding the same nearly to the level of the hole I), which is placed uppermost. The liquid,which need not wholly fill the reservoir, is thus retained at a temperature below the volatilizingpoint in the lower part of the reservoir, while the hole b in the upper part of the said reservoir is solder-(d by applying a drop of'solder in any usual manner, the heat of the said solder being unable to effect the volatilization of the liquid, owing, to the cool material surrounding the latter.

I claim- The herein-described improvement in the art or method of manufacturing thermostatic instruments, which consists in introducing a liquid into a metallic reservoir through a hole in the said reservoir, surrounding the reservoir with cooling material, and sealing the said hole while the reservoir is in the cooling material, substantially as described.

In testimony whereofI have signed my name to this specification in the presence of two subscribing witnesses.

MORRIS MARTIN.

\Vitnesses:

G. WV. GREGORY, J 0s. P. LIVERMORE. 

